Buy two extra large tee shirts:
Each dress is made of one tee shirt ( bright solid colors work best). The bust part was made out of the sleeves of the shirt, and the skirt part was the rest. The straps were made from a strip off the top of the skirt. A few seams and you're done. They are stretchy and conform to your size and shape. They are cool and comfortable and easy to wash . I recommend drying them on a hanger rather than in your dryer. For decoration you can put large colorful buttons at the base of the straps. Look pretty for a few dollars.